Sand production and high water content in oil wells are two major challenges that restrict high and stable production in loose sandstone reservoirs.In this paper,nano SiO_(2),coupling agent triethoxysilane,phenolic re...Sand production and high water content in oil wells are two major challenges that restrict high and stable production in loose sandstone reservoirs.In this paper,nano SiO_(2),coupling agent triethoxysilane,phenolic resin and n-octanol were used to synthesize the main agent SCA-2.Hexamethylenetetramine and vinyl carbonate were selected to prepare the curing agent YGA-1,which was then compounded with SCA-2 to develop a sand fixation and water plugging system.Firstly,single-factor experiments were conducted to determine the optimal concentrations of SCA-2 and YGA-1,subsequently,the system’s sand fixation and water blocking performance were evaluated.Finally,a pilot test was carried out in the mining site.Experimental results showed that the optimal formula composition of the system was 10%SCA-2+5%YGA-1.The gelation time of the system was 180 minutes and the viscosity after gelation could reach 108.4 mPa·s.When the dosage of the drug system was 0.6 PV,the sand production rate remained below 0.08%.Dual-tube parallel experiments showed that the sand fixation and water plugging system had a water flow channel plugging rate of 87.5%,while the oil flow channel plugging rate was only 11.3%,indicating minimal damage to the oil-bearing reservoir.The field test showed that after the measures taken in Well M of X oilfield,the sand free oil recovery period exceeded 360 days,the water content decreased by 5.0%and the cumulative oil production increased by 7092 m^(3).This study provides new ideas for efficient development of loose sandstone reservoirs.展开更多
Based on the characteristics of wind-sand movement in the gravel desert area along the GolmudKorla Railway,this study employs numerical simulation,wind tunnel and field measurement methods to investigate the wind-sand...Based on the characteristics of wind-sand movement in the gravel desert area along the GolmudKorla Railway,this study employs numerical simulation,wind tunnel and field measurement methods to investigate the wind-sand protection mechanisms and effectiveness of various sand control measures for the Golmud-Korla Railway.Results reveal that wind-sand flow is significantly influenced by sand barrier with notable fluctuations in wind speed observed around these barriers.In the region of 0H to 5H(H is the height of the sand barrier model)downstream the barrier,where turbulent flow disturbances are particularly intense,substantial modifications to the airflow patterns were observed.Among the three types of sand barriers tested,the horizontal wind speed fluctuations on the leeward side of the reed bundle sand barrier are the most pronounced,with the lowest wind speed attenuation coefficient reaching 0.29.Within a specific range of wind speeds,the effective protective width of a sand barrier is negatively correlated with the upstream wind speed.The reed bundle sand barrier demonstrates the largest average protection width,followed by the highdensity polyethylene(HDPE)board sand barrier,while the metal mesh sand barrier provides the smallest protection.In the gravel desert area of southern Xinjiang,the sand trapping efficiency of the reed bundle and HDPE board barriers reaches 93.85%and 96.42%,respectively,with annual maximum accumulated sand volume of 3.342 m3/m and 3.73 m3/m.Both barriers demonstrate excellent wind-sand protection effects.From an environmental sustainability and operating lifetime perspective,a three-dimensional wind-sand control system composed of two or three reed bundle sand barriers is recommended for the Golmud-Korla Railway area.This endeavor would provide valuable insights and guidance for wind-sand disaster prevention and control in the gravel desert areas.展开更多
文摘Sand production and high water content in oil wells are two major challenges that restrict high and stable production in loose sandstone reservoirs.In this paper,nano SiO_(2),coupling agent triethoxysilane,phenolic resin and n-octanol were used to synthesize the main agent SCA-2.Hexamethylenetetramine and vinyl carbonate were selected to prepare the curing agent YGA-1,which was then compounded with SCA-2 to develop a sand fixation and water plugging system.Firstly,single-factor experiments were conducted to determine the optimal concentrations of SCA-2 and YGA-1,subsequently,the system’s sand fixation and water blocking performance were evaluated.Finally,a pilot test was carried out in the mining site.Experimental results showed that the optimal formula composition of the system was 10%SCA-2+5%YGA-1.The gelation time of the system was 180 minutes and the viscosity after gelation could reach 108.4 mPa·s.When the dosage of the drug system was 0.6 PV,the sand production rate remained below 0.08%.Dual-tube parallel experiments showed that the sand fixation and water plugging system had a water flow channel plugging rate of 87.5%,while the oil flow channel plugging rate was only 11.3%,indicating minimal damage to the oil-bearing reservoir.The field test showed that after the measures taken in Well M of X oilfield,the sand free oil recovery period exceeded 360 days,the water content decreased by 5.0%and the cumulative oil production increased by 7092 m^(3).This study provides new ideas for efficient development of loose sandstone reservoirs.
基金financially supported by Gansu Province Science and Technology Program Funding(25YFFA005)the Science and Technology Research and Development Program of China Railway Corporation(2017G004-E)the Natural Science Foundation of Gansu Province,China(23JRRE0741)。
文摘Based on the characteristics of wind-sand movement in the gravel desert area along the GolmudKorla Railway,this study employs numerical simulation,wind tunnel and field measurement methods to investigate the wind-sand protection mechanisms and effectiveness of various sand control measures for the Golmud-Korla Railway.Results reveal that wind-sand flow is significantly influenced by sand barrier with notable fluctuations in wind speed observed around these barriers.In the region of 0H to 5H(H is the height of the sand barrier model)downstream the barrier,where turbulent flow disturbances are particularly intense,substantial modifications to the airflow patterns were observed.Among the three types of sand barriers tested,the horizontal wind speed fluctuations on the leeward side of the reed bundle sand barrier are the most pronounced,with the lowest wind speed attenuation coefficient reaching 0.29.Within a specific range of wind speeds,the effective protective width of a sand barrier is negatively correlated with the upstream wind speed.The reed bundle sand barrier demonstrates the largest average protection width,followed by the highdensity polyethylene(HDPE)board sand barrier,while the metal mesh sand barrier provides the smallest protection.In the gravel desert area of southern Xinjiang,the sand trapping efficiency of the reed bundle and HDPE board barriers reaches 93.85%and 96.42%,respectively,with annual maximum accumulated sand volume of 3.342 m3/m and 3.73 m3/m.Both barriers demonstrate excellent wind-sand protection effects.From an environmental sustainability and operating lifetime perspective,a three-dimensional wind-sand control system composed of two or three reed bundle sand barriers is recommended for the Golmud-Korla Railway area.This endeavor would provide valuable insights and guidance for wind-sand disaster prevention and control in the gravel desert areas.
